Apparatus for pulverizing coal and other materials.



o. A. BBT1."INGT01\I.` APPARATUS FOR PULVERIZING GOAL AND OTHER MATERIALS.

APPLICATION FILED N0.1,1909. V

Patented Sept. 23, 1913.

2 SHEETS-SHEET 1.

LOT/4,040.

C. A, BETTINGTON.

APPARATUS FOR PULVERIZING GOAL AND OTHER MATERIALS.

API'LIUATIONFILED ::ov.15,109.

l ,O'-QOQ, Patented Sept. 23, 1913.

2 SHEETS-SHEET 3.

CLAUDE ALBEMARLE BETTINGTON, 0F LONDON, ENGLAND.

APPARATUS FOR PULVERIZING COAL AND OTHER MATERIALSi Specification of Letters Patent.

Patented sept. as, 1913'.

Application led November 15, 1909. Serial No. 528,150.

To all whom t may concern.'

Bc it known that I, CLAUDE ALBEMAnLi-i Bm'rINGToN, a subject of the King of Great Britain, residing at the Junior United Service Club, 11 and 12 Charles street, St. James, and of 14 Half Moon street, Piccadilly, in the county of London, England, have `invented certain new and 'useful Improvements in and Relating to Apparatus for Pulverizing Coal and other Materials, of which the following is a specification.

This invention relates to apparatus for pulverizing coal and other materials and it has special reference to an apparatus for pulverizing coal for direct use in furnaces and the like in which' the coal in lumps is fed to a chamber or chambers having therein a series of rapidly rotating beaters which comminute the said lumps, and at the same time mix the coal with air and deliver the mixture to the furnace.

The chief object of the present invention is to provide a pulverizing apparatus which is more eflicient and economical in its action than is the case with such apparatus as has been previously proposed.

According to the present invention the pulverizing chamber is rovided with an outlet for the mixture o pulverized material and air, which outlet 1s constructed so that it forms a curve in continuation of the internal circumferential surface of the chamber. The mixture of pulverized material and air is ejected from said outlet vertically upward into a chamber provided with a suitable baflle or' baffles which cause the mixture to be deflected in a downward direction whereby the larger particles of material fall to the bottom of said chamber from which it is returned to the pulverizin chamber by suitable means. The materia to be pulverized is delivered to the pulverizing chamber at that point where the beaters immediately commence to act upon it so that said action may take place over practically the whole of the effective internal periphery of the chamber.

In order that my said invent-ion may be clearly understood and readily carried into effect, I will describe the same more fully with reference to the accompanying drawings, in which Figure 1 is a front elevation of the compie-te apparatus. Fig. 2 is a side view of the same. Fig. 3 is an elevation on a larger :ale of the pulverizing apparatus, and Fig.

4 is a sectional elevation on the line A-B of Fig. 3. Figs. 5 and 6 are respectively a sectional end elevation and a side elevation of a modified constructional form of beaters.

A is a shaft suitably connected or geared with an electric motor B or other source of power and upon the said shaft a number of eater arms A are mounted, preferably arranged in duplicate as shown 1n Fi 3, to the outer ends of which steel beater plates a are suitably attached. The said arms and the plates a serve as beaters and fan blades and rotate within a chamber A whose inner circumferential wall is preferably concentric for the greater art of its circumference with respect to tlie axis of rotation of the vanes. In the constructipnal form of beaters illustrated in Figs. 5 and 6, the beater plates a are held between two flat disks Ac which are riveted or otherwise secured to the boss A2". The said beater plates a are secured to the disks Ax by means of pins ac which are in turn retained inposition by means of pins a* arranged transversely to the pins a". If one of the beater plates a encounters a ri 'd obstruction it will swing back and allow ille said plate to pass the obstruction, the beater plate being kept in its normal position during the workingof the motor B -by the action of centrifugal force.

If desired the beater plates a mav be secured to the disks A* by means of `bolts or the like. Holes t2x may be formed in the said disks to allow communication. between the two sides thereof. The boss A2x is preferably fixed to the shaft A b means of a copper rivet or rivets a whic shear if the load becomes too great. In this event to prevent lateral movement of the beaters, the point. of a bolt as* engages in a oove a in the shaft A. The sald cham er has an opening a through which a chute B2 projects to deliver the coal in lumps to the said chamber from a worm conveyer B or other suitable feeding device connected with the source of coal supply. Another opening a, preferably on the opposite side, serves as the principal air inletumd is covered with a hood G2, which is provided with an ad- 4justable shutter a serving as the air inlet regulator. The position of the oint'of eners, and consequently of the coal and airaround the inner circumference of tlie machine and such that the said coal falls upon a lip ai3 of the casing and immediately meets an ascending beater or vane thus producing an impact which shatters the lump into small particles. The material to be pulverized is thus delivered at such point in the casing where the beaters immediately commence to act upon it. The particles rebound against the circumferential wall of the casing A2 which is preferably provided with projections or teeth A3 which assist in the reductionof the coal to tine particles and from which projections or teeth the coal rebounds, and again meets other rapidly rotating beaters or varies. The said lip as is preferably formed with a plain internal surface to insure the coal being reduced in size before it reaches the corrugated or toothed part ofthe casing. The chamber A2 is provided with an exhaust pipe Cthrough which the intimately mixed coal particles and air are ejected bythe centrifugal action produced by the beaters or vanes. The said pipe C enters the chamber A2 by means of a channel C which is integral with or suitably attached l.to the said chamber and joins thel latter at its surface to form approximately an involute curve in continuation of the internal circumferential surface of the chamber, whereby'a better result is obtained 1 from the centrifugal action produced by the beaters and the velocity imparted thereby to the coal dust by the beaters. The said curve is such that a particle projected from one of the rotating beaters, will pass easily into the said channel C. The said curve in the example shown is an involute of the internal circular surface of the chamber for a certain distance, after which it is a circle concentric,

i mixture of coal dust and air to a separating chamber D, preferably to the lower end thereof as shown in Figs. 1 and 2, the said chamber being provided with a suitable baffle D by which the current of air and coal dust is deflected. The said batlle may be in the form of a cone, wit-hin which the exhaust pipe C projects, the mixture being thus given a downward movement which causes the separating of the larger particles of coal to be more effectively obtained.

The velocity of the air after issuing from the battle is reduced, and any particles of coal which are not then sufficiently fine as to be held in suspension fall to the lower part ofthe said chamber D and pass through a suitable pipe E and its reduced continuation E2 leading therefrom preferably through the aforesaid air inlet side of the as where pulverizing chamber A2 to the li the further reduction of the particles to the required degree of ineness is completed, the

said particles being drawn into the machine by the current'of air induced b the beaters as aforesaid. The said pipe E is made sufficiently large and is preferably provided with an adjustable shutter E or the like so that in certain cases, for instance during low rates of firing, where it is desirable that the air or other gas should not fall below a certain minimum weight per unit of time,

fresh material coming in for treatment..

The separating chamber D is provided with an exhaust pipe F through which a predetermined quantity of air and coal dust entering the machine is conducted to the furnace or the like.

In certain circumstances, where for example thermal efiiciency or uniform lineness are not of primary im ortance the separating chamber may, be ispensed with and the mixtureof coal particles and air led directly from the pulverizing chamber A2 to the furnace or the like; or screens may be substituted for the said separating chamber or a centrifugal separator or other suitable device may be used.

When very wet coal or other material is to be pulverized, asis often the case,vwhich as is well known renders pulverizing more difficult, it is advantageous to use heated air or other hot gases, as a conveyin` agent. For this purpose a pipe G is suitably'connected to the hood G2 through which t-lie heated air or gases enter, the said pipe being provided with asuitable shutter G for regulating the supply or hot flue gases may .be drawn through pipe G and cold air through the opening in the hood'G2 controlled by the shutter a2 in any desired proportions.

The aforesaid apparatus has been de scribed with reference to the treatment of coal, but it 'should be understood that I do not limit myself to this particular application, as obviously it could advantageously be employed with any friable substance or mixture of substances which it is desired to reduce to a tine powder; further it could be used in a modified form for atomizing vor carbureting liquid fuels whether volatile or otherwise. Similarly when the said substance or substances are adapted, after being pulverized, to be used for purposes of combustion or partial combustion-:or to undergo heating or roasting, I4 may intimately mix the same in the manner aforesaid with gases that support combustion other than air or with combustible gases vapors or liquids or a mixture of some or all as'may be desired.

When two or more machines are working in parallel with several exhaust pipes F in connection with one common pipe communieating with the furnace, and one pulverizer is stopped, it is necessary to prevent the air and coal dust from the other pulverizers from blowing back through the stationary machine; for this purpose a shutter H is provided in the exhaust pipe F which will automatically close on the pressure in the pipe 11` exceeding that in the chamber D and will open when the pressure in the separating chamber exceeds that in the pipe F. The said shutter is pivoted and is provided with an arm carrying an adjustable Weight for setting the shutter to open when a desired pressure is reached in the separating chamber. The aforesaid Worm convcyer B is dri'en by means of the engagement of a projectinoP band b on a Wheel b mounted upon a shaft bx which is suitably geared with' the worm B with a groove or grooves formed in the shaft A'of the pulverizer. The diameters at the bottom of these grooves vary so that the speed of the Worm B can be varied by axially displacing the said wheel b to let the band b engage with one or other of the said grooves, the gearing which connects the shaft b* with the worm being such that the lowering and raising of the wheel b to engage with the various grooves, can take place.

What I claim and desire to secure by Letters Patent of the United States is In a pulverizng apparatus, the combina.- tion of a easing having teeth formed on its internal periphery and provided with an extension forming approximately an involute curve and serving as an outlet, beaters rotating in the casing, a supply chute at one side of the casing for the material to be pulverized, a substantially horizontal lip in said casing below said chute upon which the material falls, and a chute at the other side of the easing by which the coarse material is returned to said lip.

In testimony whereof I affix my signature in presence of two witnesses.

CLAUDE ALBEMARLE BETTINGTON. Witnesses:

T. SnLIsY IVARDLE, Tiros. I". HARGREAVES. 

